[sdiy] Thoughts on drum synth

[Magnus Danielson]

Hi Folks!

Now, after these discussions I have gathered my thougths some on
this...

I'll start at the drum-pad end (regardless if you have one or not).

Assuming that we have a evenly tensioned skin on a drum, there are two
parameters which decide the energy-distribution between different
nodes, one is how much off-center you hit on the drum (the angle of
the hit from the center SHOULD not mean anything - see assumption on
evenly tensioned skin!) and one is the covered size of the impacted
area. Big soft ball/finger tapping does not give the same nodal
distribution as that of a drum-stick.
This froms the distribution of the impact energy, but the impact
energy curve has to be given (measured or synthesized) into the
distribution set.

The modes themselfs is just resonances of different frequencies and
Q-values. Thus, the weighted impact energy curve is fed into its
corrensponding resonator. The output of these resonators is summed up
to go into the drum shell resonator, toss in a few spurious resonators
(other drums) and you are all set.

Some thought on how to tweak the frequencies might be worth doing.
I think you only want to tweak the fundamental mode absolute, but all
the higher modes in relative to the fundamental frequency. The
Q-settings you want absolute.

If you want more advanced control, at least a variable Q on the mode
resonators is required, to simulate selective damping control.
The weighing may be the same as the energy distribution of the impulse
energy.

So... cook up a bank of resonators.. ;O)

This strategy will also quickly kill of the non-resonat energy of the
impulse, which is quite alot actually.

Cheers,
Magnus